Grinding machine



Oct. 31, 1933. w. J. GUlLD GRINDING MACHINE 2 Sheets-Sheet 1 Filed May21, 1951 gwuvntov Jfi/CIO J Gui 1d Oct. 31, 1933. w. J. GUILD 1,933,213

GRINDING MACHINE Filed May 21, 1931 z sheets-sheet 2 womtof;

brald J. Guild Patented Oct. 31, 1933 UNITED STATES PATENT OFFICE TheHeaid Machine Company,

Worcester,

Man, a corporation of Massachusetts Application May 21, 1931. Serial No.538,969

1: Claims. (01. 51-50) The present invention relates to grindingmachines, and particularly to a machine adapted for grinding theinternal conical and cylindrical surfaces of gears. sleeves, bushingsand like articles.

The invention is directed specifically to the provision of mechanicalmeans by which a traversing movement is obtained between the grindingwheel and the workpiece.

In the constructions now in use, the reciprocation of either a grindingwheel or a workpiece in a grinding machine is obtained by manual, fluidor mechanical means. In manually operated machines, it is dimcult toobtain uniform grinding and the operation of such machines requires anunnecessary expenditure of time, especially when a. series of duplicateworkpieces'are to be successively ground. Grinding machines actuated byfluid or mechanical means are generally of complicated construction,making them expensive to build and requiring considerable care inmaintaining them in good operating condition. The

object of the present invention is accordingly to incorporate automaticreciprocatory means in a grinding machine of simple construction incombination with the advantageous features of the more complicatedautomatic machines.

According to the present invention, the grinding wheel and workpiece arerelatively reciprocat- Y ed automatically in operative relation and areautomatically separated from each other for a dressing operation on thewheel, or when the grinding operation is completed, the wheel beingreturned to operative relation with-the workpiece by manually operatedmechanism. Other objects and advantages will appear from the followingdescription. taken in connection with the accompanying: drawings, inwhich- Fig. 1 is a front elevation view of a grinding machine embodyingthe invention, parts of the base of the machine being broken away toshow the operating mechanism.

'Fig. 2 is an elevation view similar to Fig. 1,' showing the operatingmechanism in a different Fig. 0 is a diagrammatic view showing therelative positions of the operating switch and its actuating mechanism.

Fig. '7 is a wiring diagram.

Like reference characters refer to like parts throughout the drawings.

Referring first to Fig. 1, an internal grinding machine is shown havinga base or frame 1 with a reciprocatory table 2 slidable thereon, onwhich a wheelhead 3 is mounted. The work to be operated upon is heldin aworkhead 4carried by a as bridge 5 which spans the slideways provided bythe machine. frame 1 for the hack and forth movement of the table 2. Agrinding wheel 6 is carried on a spindle 7 rotatably,mounted in thewheelhead 3 and is driven in any suitable manner; a workpiece to beground is suitably held in a chuck which is mounted on the inner end ofthe workhead 4 and is also rotated by any suitable means preferably at areduced speed.

The table 2 is arranged to'be manually reciprocated by a pilot wheel 8rigidly mounted on the outer end of a shaft 9 which is journalled in abushing 10, Fig. 3, integral with the .front of the frame 1. The innerend of the shaft 9 carries a pinion, not shown, which is in engagementwith so a rack 11 horizontally mounted rigidly on the under side offthetable 2. Rotation of the pilot wheel 8 clockwise will accordingly movethe table 2 to the right, as viewed in Fig. 1, and counterclockwiserotation will move the table to the left. 5

Mechanism is provided for reciprocating the table 2 automatically whendesired. A slide member 12, Fig. 3, is provided withprojecting guides 13and 14 on opposite sides thereof which engage in grooves 15 and 16formed in the base 1 of the machine, to 'permit reciprocation of theslide longitudinally of the frame. The slide 12 is provided on the underside with a downwardly extending -.slot 1'! which is engaged by a roller18 carried on a pin on the upper end of a lever 20. The lever 20 iscentrally pivoted at 21 to the frame and is connected at the lower endby a link 22 to a second lever member 23 centrally pivoted at 24 to theframe.- A cam 25 is rigidly moimted -on a shaft 26, journalled in abearing 2'7, Fig. 3,

in a portion of the base and is rotated by means of a pair of bevelgears 28 from a pulley 30, the' latter being driven in any desiredmanner. Rotation of the cam 25 reciprocates the upper end of the lever23 which 'is in contact therewith, thereby reciprocating the lever 20and accordingly the slide 12; the cam being preferably of a shape toimpart uniform rectilinear motion to the slide. A spring 31, .one end ofwhich is connected to the frame and the other end of which ber 33 ispivotally mounted on a depending bearing 34 onthe slide 12 and normallyheld in substantially horizontal position as shown in Fig. l, byengagement of the upper surface 35, Fig. 2, of the latch with a planesurface 36 on the bearing member 34. The table 2 is provided withdownwardly extending supports 37 connected adjacent their lower end by apin 38 which is adapted to be engaged by the hook portion 40 of thelatch 33, the end of said latch being provided at the end adjacent thehook 40 with a slanting surface 41, Fig. l, which permits the end of thelatch to ride up over the pin as the table and slide are broughttogether. when the table and slide are connected together in thismanner, the grinding wheel is reciprocated past the work surface betweenthe limits of the full and dotted lines of Fig. 4, by the reciprocatingslide. Release of the table from the slide is effected by upwardmovement of the latch, said release being obtained in a manner to behereinafter pointed out, thereby to disengage the hook 40 of thelatch'from the pin 38.

when the latch is-released from the pin, the table 2 is caused to movesomewhat beyond the normal reciprocatory stroke in order to move thegrinding wheel from the operative reciprocatory limits of Fig. 4, to theposition of Fig. 5, in which the wheel is spaced from the workpiece ininoperative relation. A plunger 42 is mounted in an opening 43 in theslide, and a spring 44 engages beneath the plunger resiliently holdingsaidplunger outwardly to the extreme right end of its movement. A pin 45which acts as a guide for the plunger is mounted on the outer end of theplunger 42' and projects through an opening in the cap 46 which coversthe opening in the slide to engage with a vertical surface 47, Fig. 1,on the under side of table 2. As the table and slide are 1 broughttogether, the table engages the pin and depresses the plunger in theopening in the slide against the pressure of the spring, so that whenthe latch is subsequently released, the action of the spring on the pinand plunger forces the table away from the end of the slide a distanceequal to the amount the spring was previously compressed, duringconnection of the table and slide.

In grinding machines of this type a cross-feed movement is provided tocause the grinding wheel to be fed transversely, in order to cutprogressively deeper and deeper into the workpiece. This may be eflected by the mechanism disclosed in the patent to Taylor No. 1,682,673,issued August -2a, 1928 and is not of itself the invention in thisapplication. It is suilicient, for the present purposes, to say'that aratchet wheel 48 is operatively connected to a shaft 49, the latterbeing screw threaded and engaging a threaded nut in a cross-slide on thetable 2, said cross-slide carrying the wheelhead 3, so that rotation ofthe ratchet wheel causes in and out movement of the wheelhead. Theratchet wheel 48 is actuated by a pawl 50 which is pivotally mounted onan arm 51', Fig. 2, a portion of the arm being arranged to e age with anadjustable cam surface 52 mounted on a horizontal extension of thebridge 5. Reciprocatory movement of the table 2 causes engagement ofsaid cam with the pivotally mounted arm 51 thereby actuating saidratchet with each reciprocation of the table to impart a step-bysteprotary movement to the ratchet wheel and,

accordingly, a-step-by-step cross-feed movement to the grinding wheelcarried by the wheelhead 3. A cam 53 is mounted to rotate with saidratchet wheel and is arranged to engage successively with adjustablescrews 54 and 55, engagement with the screw 54 closing a circuit wherebythe table is released from the reciprocating slide and subsequentengagement with the screw 55 again disengaging the table from the slide.

The separation of the table 2 from the slide 12 by engagement of the cam53 with the screw 54 is'obtained through an electrical circuit in thefollowing manner:

As shown by the wiring diagram of Fig. 7, the power is supplied by agenerator 58, one terminal of which isconnected to a ground 57 by a lead58, the other terminal being connected to one terminal of anelectromagnet 60 by a lead 61. The other terminal of the electromagnetis connected by a lead 62 to a stationary plate 63 of a switch 64, theother plate 65 thereof being connected by the screw 54 by a lead 66.Movement of the adjusting screw 54 by the cam surface 53 makes a contactbetween terminals 67 and 68; terminal 67 being in electrical contactwith the adjusting screw 54, the terminal 68 being con-- nected to aground 70 by a lead 71. When the terminals 67 and 68 are in contact, thecircuit through switch 64 to the electromagnet 60 is closed and themagnet 60 is energized, thereby causing attraction or an armature member72, Fig. 1. This armature 72 is connected through a link 73' to a lever74 pivotally mounted on the machine frame below the latch 33, attractionof the armature by the magnet 60 raising one end of the lever 74 intoengagement with a slanting surface'75 on the latch as shown in Fig. 2.As the latch is carried toward the right, Fig. 1, by the slide 12, thelever 74 raises the latch so that the hook of said latch is disconnectedfrom the pin 38 at the extreme right hand movement of the slide,releasing the table from the slide.

After the latch is disengaged from the pin, the spring actuated plunger42 moves the table to the right into inoperative position, as abovepointed out, moving the grinding wheel into the position shownin Fig. 5.Movement of the table in response to the action of the plunger 42disconnects the switch 64 thereby to open the above circuit and releasethe armature of the electromagnet to allow the latch to drop into normalpin engaging position in the following manner. The plate 65 of theswitch. 64 is pivotally mounted at 76,

Fig. 6, and is provided with a lug 77 which is in alignment with theouter end of an arm 78 pivotally mounted at'79 on the frame 1 andhanging by gravity in the position shown in Figs. .1 and 6.

As the table moves to the right, the arm 78 endressing operation isperformed onthe wheel. A

pivotally mounted dressing point 80 which is arranged for manualrotation is moved into line to the finishing cuts on the workpiece.

After the dressing operation the wheel is manually returned to theworkpiece by counterclockwise rotation of pilot wheel 8, so that thelatch 33 again engages the pin 38 for further automatic reciprocation ofthe grinding wheel on the work surface to complete the workpiece. Thiscontinued reciprocation again actuates the pawl 50 and ratchet 48 andfurther rotates the cam surface until it'engages with and lifts theadjusting screw 55, thereby closing a circuit to actuate again said armor lever 74' so that the wheel and work are again separated. Thisseparation occurs in the following manner:-

Referring to the 'wiring diagram of Fig. 7, the adjusting screw 55 isconnected to the lead 62 by a lead 81. Movement of the adjusting screw55 causes contact between two terminals 82 and 83, the terminal 82 beingelectrically connected to the adjusting screw 55 and the terminal 83being connected to the ground 70 by a lead 84. Accordingly, connectionof the terminals 82 and 83 closes the circuit through an energizes theelectromagnet and again actuates \he lever 74, as above pointed out. torelease the table from the reciprocating slide in the manner above setiorth, the wheel being again separated from the work by the springactua-ed plunger. The workpiece being now completed, the wheel ismanually withdrawn from the workpiece a sum-- cient distance to permitremoval of the workpiece from the work-holding chuck.

when a new workpiece has been inserted, the table is again returned tothe normalbpera'ing position. During this return movement an arm 85,pivotally mounted at '79 on the frame and held by gravity in theposition shown in Fig. 6, engages a lug 86 on the switch 64 returning itto the full line positionof Figs. 6 and 7, completing the connectionsbetween the screw 54 and the electromagnet 60, so that during asubsequent grinding operation when the adjusiing screw 54 is actuated bythe cam 53, the circuit is closed through the switch 64 to theelectromagnet 80, and the lever 74 is again actuated to release thetable from the reciprocating member. Before the return of the wheel intoengagement with an unground workpiece, the ratchet wheel 48 is rotatedcounterclockwise to reposition the wheel for engagement wi'h the surfaceto be ground of a subsequent workpiece. This repositioning move- I .mentwithdraws the cam 53 from engagement with screws 54 and 55 and placesthe cam' in a position for engagement with said screws during asubsequent grinding operation in response to clockwise rotation of saidratchet wheel.

I claim; 1. In a grin machine, a grinding wheel, a

reciprocating m ber, means connecting said d nember to the wheel. toprocure reciprocation of wheel in operative relation to a workpiece. andmeans to procure separation of said member and wheel.

2.-Inagrindingmachine,agrmdingwheel,a reciprocating member, meansconnecting said member to the wheel to procure reciprocation of thewheel in operative relation to a workpiece, and automatic means governedby the ,progress of the grinding operation to disconnect said member andwheel to procure cessation of the reciprocation of the wheel.

carriage from said slide member at 4. In a grinding machine, a grindingwheel, a I

mechanica ly actuated reciprocating member having an adjustable stroke,means releasibly connecting said wheel and member to procurereciprocation of the wheel in operative relation to a workpiece, meansto procurea cross-feed movement of said wheel relative to said workpieceand means responsive to said-latler means to procure cessationoi thereciprocation of the wheel.

5. In a grinding machine, a grinding member and a workhoiding-member,cross-feed means to procure a transverse feed relative to a workpiece insaid workhoiding member, a reciprocating slide, means'to connect saidslideto one of said members to procure reciprocation of said wheel inoperative relation to the workpiece and means responsive to saidcross-feed means. to disconnect said slide from the member to which itis connected to procure cessation of the reciprocation and withdrawal ofthe wheel from the work.

6. In a grinding machine, a grinding member and a workholding member, ,acarriage upon which one oi said members is mounted, means to procure atransverse feed belween said members, means to procure a reciprocationbetween said members comprising a continually reciprocating member andmeans to connect said carriage thereto, and means responsive to saidtransverse feed means to disconnect said carriage and reciprocatingmember to procure cessation of reciprocation belween said members.

- 7. In a grinding machine, a grinding member and workholding member, acarriage carrying one of said members, a reciprocating slide member,

means to connect said carriage and slide member to procure areciprocation of said grinding member in operative relation to theworkholding member, and automatic means governed by the progress of thegrinding operation to release said one end of the stroke thereof.

8. In a grinding machine. a grinding member and workhoiding member, acarriage carrying one of said members, a reciprocating slide member,means to connect said carriage and slide member to procure areciprocation of said grinding member in operative relation to the'workholding member, means to release said carriage from saidslidemember at one end of the stroke thereof, and means operative uponrelease of said carriage to procure movement of said carriage be .yondthe normal reciprocatory position,

workpiece, means responsive to the movement of said cross-feedmechanismto. discontinue the reciprocation of. said wheel by releasingsaid wheel from said member and means to render said last meansinoperative following release of said wheel.

10. In' a grinding machine, a grinding wheel,

a reciprocating member, means to connect said wheel to said member toprocure reciprocation or said wheel in operative relation to aworkpiece, a cross-teed mechanism to procure a transverse movementbetween said wheel and workpiece, electrical means responsive tomovement of said crow-feed mechanism to discontinue. reciproca tion saidwheel by releasing said wheel from said member, and means to render saidelectrical means inoperative upon release of said wheel.

11. In a grinding machine, a grinding wheel, a reciprocating member,means to connect said wheel to said member to procure reciprocation ofsaid wheel in operative relation to a workpiece, a cross-feed mechanismto procure a transverse movement between said wheel and workpiece,

electrical means including an electromagnet responsive to movement ofsaid cross-teed mechanism to discontinue reciprocation of said wheel byreleasing said wheel from said member, means to open a circuit to saidmagnet upon release or said wheel from said reciprocating member torender said electrical means inoperative and means responsive to furthermovement 0! said cross-feed mechanism to close a circuit to saidelectromagnet means.

12. In a grinding machine, a carriage, a reciprocating member, a latchon one of said parts, a

pin ;engageable therewith on the other of said parts, means on saidlatch to permit automatic engagement of said latch and pin when saidparts are brought together, and automatic means governed by theprogress-oi the grinding operation to v actuate said latch to releasesaid pin at one end or the stroke of the reciprocating member.

13. In a grinding machine, a grinding member and a workholding member, areciprocating slide, means releasably connecting said slide to one ofsaid members to procure the reciprocation of said grinding member inoperative relation to a workpiece in the workholding member, and meansto procure separation of said slide and the member connected theretoupon release of said connect- 11 8 means.

14. In a grinding machine, a grinding member and a workholding member, areciprocating slide, means connecting said slide to one or said membersto procure reciprocation of the grinding member in operative relation toa workpiece, and automatic means governed by the progress or thegrinding operation to disconnect said slide from the member to which itis connected to procure cessation of ,the reciprocation o! the grindingmember. relative to the workpiece.

15. In a grinding machine, a grinding member and a workholding member, areciprocating slide, means connecting said slide to one-oi said membersto procure reciprocation of the grinding member relative to a workpiecein the workholding member, and automatic means operative when theworkpiece reaches a predetermined size for disconnecting said slide fromthe member to which it is connected to procure cessation of thereciprccation of the grinding member relativeto the workpiece.

16. In a grinding machine, a grinding member and a workholding member, acontinuously reciprocating slide, means connecting said slide to one ofsaid members to procure reciprocation of the grinding member relative toa workpiece in the workholding member,- means to disconnect said slidefrom the member to which it is connected to procure cessation of thereciprocation of the wheel, and means to procure the withdrawal of saidgrinding member from the workpiece upon the cessation of thereciprocation.

1'7. In a grinding machine, a grinding member and a workholding member,a reciprocating slide, means to connect said slide to one 01' saidmembers to procure reciprocation of the grinding member in operativerelation to a workpiece in the workholding member, electrical meansgoverned by the progress of the grinding operation to discontinuereciprocation of said grinding member by releasing said slide from themember to which it is connected, and means to render said electricalmeans inoperative upon release of said slide.

18. In a grinding machine, a grinding member and a workholding member, areciprocating slide, means to connect said slide to one or said membersto procure reciprocation oi the grinding member in operative relation toa workpiece in the workholding member, and electrical means operativewhen the workpiece in the workholding member reaches a predeterminedsize to discontinue reciprocation of said grinding member by releasingsaid slide from the member to which it is connected.

WALDO J. GUILD;

